De Potter P, Flanders A E, Shields J A, Shields C L, Gonzales C F, Rao V M
Ocular Oncology Service, Wills Eye Hospital, Philadelphia, PA.
Arch Ophthalmol. 1994 Mar;112(3):340-8. doi: 10.1001/archopht.1994.01090150070026.
Recent studies have shown that contrast (gadopentetate dimeglumine)-enhanced magnetic resonance imaging is useful in evaluating intraocular tumors and differentiating uveal melanoma from other simulating lesions. The purpose of this study was to study prospectively the role of fat-suppression technique and gadopentetate dimeglumine-enhanced magnetic resonance imaging in the evaluation of intraocular neoplasia.
Forty-three uveal melanomas and 20 other simulating intraocular lesions from 63 patients were prospectively evaluated on non-contrast-enhanced and post-contrast-enhanced T1-weighted images with and without fat-suppression technique and on T2-weighted images.
Forty-one uveal melanomas (95%) were detected with standard pulse sequences and showed the characteristic hyperintense signal on non-contrast-enhanced T1-weighted images and hypointense signal with respect to the vitreous on T2-weighted images. All 33 uveal melanomas evaluated on non-contrast-enhanced T1-weighted images with fat-suppression technique were detected on non-contrast-enhanced images with fat-suppression technique. The intensity of the signal was statistically associated with the degree of pigmentation of the tumor on T1-weighted images with fat-suppression technique (P = .03). On post-contrast-enhanced T1-weighted images with or without fat-suppression technique, the 43 uveal melanomas showed enhancement. The degree of tumor enhancement was not statistically related to the degree of tumor pigmentation or the location of the tumor. Among the other simulating intraocular lesions, choroidal metastasis, retinoblastoma, choroidal leiomyoma, and medulloepithelioma demonstrated the same features on magnetic resonance imaging studies as uveal melanoma demonstrated on non-contrast-enhanced and post-contrast-enhanced T1-weighted images with or without fat-suppression technique. In our series, choroidal hemangioma, choroidal osteoma, posterior scleritis, retinal hemangioma, and Coats' disease can be differentiated from other amelanotic intraocular tumors by their characteristics on magnetic resonance imaging studies.
We concluded that pre-and post-contrast-enhanced T1-weighted images with fat-suppression technique are most helpful in detecting small intraocular tumors with a thickness of more than 1.8 mm and in evaluating intraocular neoplasms and simulating lesions, particularly when T2-weighted images are not available. Moreover, in juxtapapillary choroidal or retinal tumor, fat-suppression technique may help in the detection of possible optic nerve or orbital extension by improving the conspicuousness of the tumor.
近期研究表明，对比剂（钆喷酸葡胺）增强磁共振成像在评估眼内肿瘤以及鉴别葡萄膜黑色素瘤与其他类似病变方面很有用。本研究的目的是前瞻性地研究脂肪抑制技术和钆喷酸葡胺增强磁共振成像在眼内肿瘤评估中的作用。
对63例患者的43例葡萄膜黑色素瘤和20例其他类似眼内病变进行前瞻性评估，采用有无脂肪抑制技术的非增强和增强后T1加权图像以及T2加权图像。
41例（95%）葡萄膜黑色素瘤通过标准脉冲序列检测到，在非增强T1加权图像上表现为特征性的高信号，在T2加权图像上相对于玻璃体表现为低信号。在采用脂肪抑制技术的非增强T1加权图像上评估的所有33例葡萄膜黑色素瘤，在采用脂肪抑制技术的非增强图像上均被检测到。在采用脂肪抑制技术的T1加权图像上，信号强度与肿瘤色素沉着程度具有统计学相关性（P = 0.03）。在采用或未采用脂肪抑制技术的增强后T1加权图像上，43例葡萄膜黑色素瘤均有强化。肿瘤强化程度与肿瘤色素沉着程度或肿瘤位置无统计学相关性。在其他类似眼内病变中，脉络膜转移瘤、视网膜母细胞瘤、脉络膜平滑肌瘤和髓上皮瘤在磁共振成像研究中表现出与葡萄膜黑色素瘤在采用或未采用脂肪抑制技术的非增强和增强后T1加权图像上相同的特征。在我们的研究系列中，脉络膜血管瘤、脉络膜骨瘤、后巩膜炎、视网膜血管瘤和科茨病可通过磁共振成像研究中的特征与其他无色素眼内肿瘤相鉴别。
我们得出结论，采用脂肪抑制技术的增强前后T1加权图像在检测厚度超过1.8 mm的小眼内肿瘤以及评估眼内肿瘤和类似病变方面最有帮助，特别是在没有T2加权图像时。此外，在视乳头旁脉络膜或视网膜肿瘤中，脂肪抑制技术可能通过提高肿瘤的显见度有助于检测可能的视神经或眼眶侵犯。
